In the course of changing energy policy in Germany, the generation of electricity from wind energy increased by a factor of 5 and from photovoltaics by a factor of 150, between 2001 and 2011. For the alignment of electricity generation from fluctuating and decentralized energy sources with electricity demand, stationary energy stores are increasingly prevalent. In response to increasing demand for stationary energy stores, 100,000 domestic solar storage batteries are expected to be installed by 2018 in Germany alone.
For an optimum exploitation of the storage capacity of individual energy stores, these may be combined to form a virtual power plant. At present, projects for the combination of decentrally dispersed electrical energy storage systems to form a virtual power plant are only at the preliminary development or trial stages. Conventionally, balancing systems at individual storage system level or battery module level are known.
U.S. Pat. No. 7,609,031 B2 discloses a method for the balancing of secondary lithium cells and modules. A battery stack control module is disclosed for the balancing of a plurality of secondary lithium cells or groups of secondary lithium cells which are electrically connected in series.
US 2013/0134943 A1 discloses a method for balancing of a battery having a plurality of parallel-connected branches, wherein each branch comprises at least two electrochemical cells which are connected in series.
WO 2012/130400 A1 discloses a circuit arrangement for the exchange of electrical charge between the interior cells of an accumulator block arrangement, wherein an accumulator block, via its external connection terminals, is interconnected with a plurality of accumulator blocks in an accumulator block arrangement.